R/make_id.R

In iholzleitner/facefuns: Convenience Functions Around 2D and 3D Face Shape Analysis

#' Make ID
#'
#' Make IDs with fixed length and a prefix (e.g., S001, S002, ..., S100).
#' @param n the number of IDs to generate (or a vector of numbers)
#' @param prefix the prefix to the number (default "S")
#' @param digits the number of digits to use for the numeric part. Only used if this is larger than the largest number of digits in n.
#' @param suffix the suffix to the number (default "")
#'
#' @return a vector of IDs
#' @export
#' @examples
#' make_id(20, "SUBJECT_")
#' make_id(10:30, digits = 3)
#'
make_id <- function(n = 100, prefix = "S", digits = 0, suffix = "") {
  if (!is.numeric(n)) stop("n must be numeric")

  if (length(n) == 1) n <- 1:n

  max_digits <- as.character(n) %>%
    nchar() %>% max() %>% max(digits)
  max_decimal <- as.character(n)
    # remove whole number parts
    # (don't use n%%1 because floating point precision)
  max_decimal <- sub("(^\\d*\\.|^\\d*$)", "", max_decimal ) %>%
    nchar() %>% max()
  fmt <- paste0(prefix, "%0", max_digits, ".", max_decimal, "f", suffix)

  sprintf(fmt, n)
}